Project Summary/Abstract Aberrant proliferation and altered metabolism are hallmarks of cancer cells. To proliferate, tumor cells must adapt their metabolism to acquire nucleotides, proteins, and lipids to support growth and division. Although altered metabolism to fulfill these biosynthetic needs is observed in all cancer cells, how metabolic demands are met in different tissue contexts and whether this affects the ability of cancer cells to proliferate in different metastatic sites is not well understood. This is particularly important as metastatic cancer is more difficult to treat than primary cancer, and tissue environment can influence response to therapy. This suggests that understanding context-dependent alterations in tumor cell metabolism could allow the design of better therapies that exploit tumor cell dependencies at metastatic sites and improve cancer outcomes. The proposed work will assess whether non-genetic determinants such as tissue context alter metabolic dependencies of tumor cells. To do this, I will implant cancer cells derived from either mutant Kras/p53-null- driven mouse models of non-small cell lung carcinoma (NSCLC) or pancreatic ductal adenocarcinoma (PDAC) into their respective tissue of origin and into metastatic sites. I will then study tumor metabolism in these different sites by infusing conscious mice with labeled nutrients and trace the fate of these nutrients into TCA metabolites, nucleotides, proteins, and lipids. I will also use CRISPR/cas9 tools to deplete enzymes required for glucose, glutamine, and protein uptake and assess tumor formation in primary and metastatic sites. The results of these studies will be the first to show whether metabolic dependencies of cancer cells change depending on tissue context. This is important, as current treatments for metastatic disease focus on primary cancer and not the location of metastatic cancer. These experiments will shed insight into whether metabolic adaptations are cell-intrinsic or mediated by the tissue microenvironment and improve our understanding of metastatic disease. Furthermore these studies may reveal new ways to block growth of metastatic tumors based on blocking their unique metabolic pathways.